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Yohan

@yohan.so.bsky.social

Sharing insights from the intersection of geospatial data science and economics | PhD in Economic Geography from LSE | Data Scientist at ADB. Views are my own. Newsletter: http://spatialedge.co

264 Followers  |  60 Following  |  901 Posts  |  Joined: 31.10.2023  |  1.6487

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29.04.2025 11:13 โ€” ๐Ÿ‘ 2    ๐Ÿ” 1    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

๐˜๐—น;๐—ฑ๐—ฟ

1. nightlights can capture certain elements of consumption and production

2. the level of granularity when using nightlights really matters

29.04.2025 11:13 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

๐—ง๐—ต๐—ฒ ๐—ธ๐—ฒ๐˜† ๐˜๐—ฎ๐—ธ๐—ฒ๐—ฎ๐˜„๐—ฎ๐˜†:

The more you zoom in, the bigger these spatial mismatches between daytime and nighttime economic activity become.

29.04.2025 11:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

This underrepresentation occurs even if:

โ€ข these areas generate a lot more economic activity (e.g. financial districts), compared to
โ€ข areas bustling with bars and restaurants

These nightlife areas tend to be overestimated in nightlights data.

29.04.2025 11:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

As a result, it's likely that I:

โ€ข work during the day in one 500m2 pixel and
โ€ข spend money in a different pixel at night.

This implies that pixels with higher daytime economic activity will be systematically underrepresented in nightlights data.

29.04.2025 11:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

This creates a discrepancy between areas where economic activity is generated during the day (London) vs at night (Essex).

With nightlights we can zoom into areas as small as 500m2.

29.04.2025 11:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

In this example, the economic activity from my job in London doesn't get picked up by nightlights.

However, the places where I spend money at night in Essex, like restaurants, do light up and are visible from space.

29.04.2025 11:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

2. Spatial Mismatches

Imagine I work in London but live in Essex, an hour away.

My work (i.e. production) contributes to London's economy.

But when I spend time in Essex, like eating out at night, that's where my consumption mainly happens.

29.04.2025 11:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

The bottom line:

Nightlights can capture certain elements of consumption AND production.

So when doing an analysis using nightlights, we need to know the composition of production and consumption.

This is important to avoid double counting.

29.04.2025 11:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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See this image of the Pilbara region in Australia

Here we see:

1. lights generated from mines being lit up at night (i.e. production-based economic activity), AND

2. lights generated by mining staff who are eating out at night (e.g. consumption-based economic activity).

29.04.2025 11:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

But the reality is a bit more complex.

Nightlights can capture some production-related activities.

E.g. nighttime construction and nighttime mining.

29.04.2025 11:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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However, we need to be careful about double counting.

E.g. combining production values with income and consumption figures without accounting for overlaps could distort things.

Henderson et al., essentially view nightlights as a measure of nighttime consumption:

29.04.2025 11:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

However, GDP is typically measured in three ways:

1. Adding up all of the consumption in an economy

2. Adding up all of the income earned in an economy

3. Adding up the value of all things produced in an economy

For an entire country, these should equal one another.

29.04.2025 11:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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1. Economic Activity

Itโ€™s vague to say nightlights capture โ€˜economic activityโ€™.

What ๐™š๐™ญ๐™–๐™˜๐™ฉ๐™ก๐™ฎ do we mean by economic activity?

The most popular paper on nightlights and economic activity is Henderson et al. (2012).

It uses nightlights as a proxy for real GDP growth.

29.04.2025 11:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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If you're using nightlights you need to know about two things:

1. What ๐™ฉ๐™ฎ๐™ฅ๐™š of economic activity it captures, and
2. ๐™Ž๐™ฅ๐™–๐™ฉ๐™ž๐™–๐™ก ๐™ข๐™ž๐™จ๐™ข๐™–๐™ฉ๐™˜๐™๐™š๐™จ

Here's the breakdown (in simple terms):

29.04.2025 11:13 โ€” ๐Ÿ‘ 3    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

So: while AI is clearly going to play a massive role in geospatial analysis going forward, could it actually be overhyped?

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

๐—ช๐—ต๐˜† ๐˜๐—ต๐—ถ๐˜€ ๐—ฎ๐—น๐—น ๐—บ๐—ฎ๐˜๐˜๐—ฒ๐—ฟ๐˜€

At the end of the day, autonomous GIS could make spatial analysis:

โ€ข More accessible to non-experts.
โ€ข Faster and more scalable.
โ€ข Capable of generating new insights.

It also forces GIScience to rethink education, ethics, and what it means to โ€œknowโ€ geography

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

โ€ข Modeling: Automating complex analysis like disease spread or flood risk still requires human judgment.
โ€ข Trust and ethics: Who is responsible if a model makes a bad call? How do we ensure fairness?

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

However, several big hurdles remain:

โ€ข LLMs lack of GIS-specific knowledge (e.g., projections, spatial joins).
โ€ข Skills gap: LLMs donโ€™t always know what tools to use or how to handle large files.
โ€ข Continuous learning: Most models canโ€™t improve themselves after deployment.

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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โ€ข ๐—Ÿ๐—Ÿ๐— -๐—–๐—ฎ๐˜: Makes maps iteratively and improves them based on its own visual critique.
โ€ข ๐—š๐—œ๐—ฆ ๐—–๐—ผ๐—ฝ๐—ถ๐—น๐—ผ๐˜: Helps QGIS users do analysis more efficiently.

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

๐—ช๐—ต๐—ฎ๐˜ ๐—–๐—ฎ๐—ป ๐—œ๐˜ ๐——๐—ผ ๐—ง๐—ผ๐—ฑ๐—ฎ๐˜†?

The authors provide working examples:

โ€ข ๐—Ÿ๐—Ÿ๐— -๐—™๐—ถ๐—ป๐—ฑ: Automatically finds and downloads the right geospatial data.
โ€ข ๐—Ÿ๐—Ÿ๐— -๐—š๐—ฒ๐—ผ: Runs a complete spatial analysisโ€”e.g., walkability around schoolsโ€”by creating code and visualizing results.

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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๐—ฆ๐—ฐ๐—ฎ๐—น๐—ฒ๐˜€ ๐—ผ๐—ณ ๐—ข๐—ฝ๐—ฒ๐—ฟ๐—ฎ๐˜๐—ถ๐—ผ๐—ป

There are three technical scales:

1. Local: Runs on a single machine
2. Centralized: Uses cloud computing to handle larger tasks.
3. Infrastructure-scale: Distributed systems for massive analysis, possibly run by governments or research institutions.

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

๐—›๐—ผ๐˜„ ๐—œ๐˜€ ๐—œ๐˜ ๐—•๐—ฒ๐—ถ๐—ป๐—ด ๐—•๐˜‚๐—ถ๐—น๐˜?

The core of an autonomous GIS is the โ€œdecision coreโ€. This is typically an LLM that:

โ€ข Reads your question.
โ€ข Plans a solution.
โ€ข Finds and cleans the data.
โ€ข Runs the analysis (e.g., in Python or GIS software).
โ€ข Presents results (maps, stats, reports).

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Most current prototypes are at Level 2.

I.e. they can follow instructions, create workflows, and run them, but need help getting the right data or interpreting results.

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น ๐Ÿฎ: Generates and runs workflows, but still needs human-provided data.

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น ๐Ÿฏ: Selects and prepares its own data.

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น ๐Ÿฐ: Understands and refines results without help.

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น ๐Ÿฑ: Fully independent, learns from experience, and adapts over time.

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น๐˜€ ๐—ผ๐—ณ ๐—”๐˜‚๐˜๐—ผ๐—ป๐—ผ๐—บ๐˜†

Autonomous GIS can be built gradually. The authors define five levels:

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น ๐Ÿฌ: Everything is manual โ€“ traditional GIS.

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น ๐Ÿญ: Automates repetitive tasks, but a human sets them up.

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

๐Ÿฏ. ๐—ฆ๐—ฒ๐—น๐—ณ-๐˜ƒ๐—ฒ๐—ฟ๐—ถ๐—ณ๐˜†๐—ถ๐—ป๐—ด โ€“ It checks its own work step by step and ensures results are reasonable.
๐Ÿฐ. ๐—ฆ๐—ฒ๐—น๐—ณ-๐—ผ๐—ฟ๐—ด๐—ฎ๐—ป๐—ถ๐˜‡๐—ถ๐—ป๐—ด โ€“ It manages time, data, compute power, and even collaborates with other agents.
๐Ÿฑ. ๐—ฆ๐—ฒ๐—น๐—ณ-๐—ด๐—ฟ๐—ผ๐˜„๐—ถ๐—ป๐—ด โ€“ It learns from experience and gets better.

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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There are 5 goals for autonomous GIS:

๐Ÿญ. ๐—ฆ๐—ฒ๐—น๐—ณ-๐—ด๐—ฒ๐—ป๐—ฒ๐—ฟ๐—ฎ๐˜๐—ถ๐—ป๐—ด โ€“ It creates ideas, workflows, code, and insights on its own.
๐Ÿฎ. ๐—ฆ๐—ฒ๐—น๐—ณ-๐—ฒ๐˜…๐—ฒ๐—ฐ๐˜‚๐˜๐—ถ๐—ป๐—ด โ€“ It can run the tasks (e.g., calculating distances, drawing maps).

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

The emergence of LLMs, has made this possible. These models can:

โ€ข Interpret instructions in natural language.
โ€ข Generate workflows and code.
โ€ข Work iteratively to refine outputs.

This opens the door to GIS reasons and adapts.

28.04.2025 11:29 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

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